1. Field of the Invention
The present invention relates to a group-III nitride semiconductor laser device, and a method for fabricating the group-III nitride semiconductor laser device.
2. Related Background Art
Non-patent Document 1 (Jpn. J. Appl. Phys. Vol. 35, (1996) L74-L76) describes a semiconductor laser made on a c-plane sapphire substrate. The mirror faces of the semiconductor laser are formed by dry etching. The Document 1 shows micrographs of the laser cavity mirror faces of the laser, and describes that the roughness of the end faces is about 50 nm.
Non-patent Document 2 (Appl. Phys. Express 1 (2008) 091102) describes a semiconductor laser formed on a (11-22) plane GaN substrate. The mirror faces of the semiconductor laser are formed by dry etching.
Non-patent Document 3 (Jpn. J. Appl. Phys. Vol. 46, (2007) L789) describes a gallium nitride (GaN)-based semiconductor laser. It proposes generation of laser light polarized in an off direction of the c-axis of the substrate, in order to use m-plane cleaved facets for the laser cavity. Specifically, this Document describes increase of the well thickness on a nonpolar surface and decrease of the well thickness on a semipolar surface.